Be concise. Get straight to the point, while making sure you cover all the important points, while also maintaining partner's interest.
Convey your “3 things”, the points that you want partners to remember about your company. Even if the conversation sways in other directions, it is your job to find a way to bring those key points back into the discussion.
Don't be defensive, and don't use jargon. Make it easy to understand you, and show that you can take and evaluate criticism. Have a lead speaker, but also enable the rest of the team to answer some of the questions.
Lastly, be confident. Remember that you’re the expert in your business. You know much more about the space than the partners interviewing you. Walk into the room knowing that you understand this subject better than anyone else.