Assuming you have a 15 minute block, plan on 12 minutes for your presentation. The remaining time will be for questions/setup.
Think of the visuals you will make (i.e., slides). Roughly, On average, slides take about 1.5 minutes or so per slide, so you'll have only about 8 slides!
Everyone in the group talks. Work out the transitions for who says what.
Your talk should start broad, like your report introduction, but narrow to a problem statement early. Then, related work, methodology, results and conclusions, possibly a demo in the middle.
Make sure to have a conclusion. This revisits the problem and methodology briefly then states what you built/did/found concretely. You don't conclude "there is more to be done" nor conclude "our code has bugs". You state unapologetically, firmly, what you did.
Don't focus on your slides too long, other than to glance at them or point out some part. Instead look at the audience.
Tip: If looking at the audience makes you nervous, try looking just over the tops of their heads.
Tip: Being nervous is ok and normal. Remember, the audience is on your side. They want you to succeed in your talk!
Don't read your slides.
Remember, you've been working on your project for 2+ months, but your audience is just learning about it today. Take the time to introduce difficult/new content (i.e., don't just jump in).
Make sure slide fonts are not too small. Everyone will be further away from your slides than you. Make use of white space on the slides to increase font sizes as much as possible.
Don't have paragraphs of text or even sentences. You don't want the audience reading your slides. The slides are mostly so they can follow along with your talk, but listening to you for content and not reading.
If you have complicated graphs/figures, make sure you take the time to explain them. First, explain axes and trendlines. Then, tell the audience what messages they should see in the figure.
Acknowledge those that helped/mentored you - this includes any project sponsors but also fellow students or WPI faculty. Be generous with giving credit - this is good professional advice to apply the rest of your career.
If you have a live demo planned, have a backup in case it fails.
Don't apologize for anything or say other defacing comments (e.g., "I'm not prepared ..."). This will subconsciously make the audience immediately downgrade your talk. Prepare as best you can (see next bullet), then deliver it as if all is going according to plan.
Practice, practice, practice! The way to give a good talk is to rehearse. Since your talk is 15 minutes, you can do 4 complete runs in as little as an hour. Do this!