There's a lot of possible ways of presenting it. You could present the philosophy, like a quick overview. I think that has limitations. You might peak their curiosity, but they might just think you're strange.
You could discuss instead what Objectivism has to offer. Why it's useful, and why they should look into it. That's different from trying to sketch out the philosophy, although you might give some details for clarification.
One approach I've been thinking about is discussing the issues in each branch of philosophy that is most important to an outsider. For instance.
1.) The nature of emotions and their connection to reason. Not many people understand this connection, and so end up waging a war inside themselves pitting the two against each other.
2.) Expanding on the first point, talk about the objective requirements for happiness, and that there are objective requirements for happiness. Happiness isn't anything goes. The emotion is not a primary...it's a consequence. And if you want real happiness, some means are better than others in achieving it.
3.) Morality as a guide to choosing values/actions. We make choices all the time, and yet most people don't try to understand their decision making process. Are they being consistent? Are they relying too heavily on their emotions because they can't see how to logically compare the choices? That's what ethics is all about. Learning to compare and contrast every possible value, and choose competently between them, instead of just a set of rules they have to follow.
4.) Capitalism as a system of freedom. Show that freedom vs. statism is the important comparison, and bash the left/right political spectrum false dichotomy. Show that it's not theft for the rich vs. theft for the poor and bash the usual communist/fascist dichotomy.
Another thought is to discuss the inevitability of philosophy. How you don't have a choice about having one, only the choice to analyze it and correct it. Rand's "Philosophy: Who Needs It" essay is a good source.
And my last thought, project the consequences of your views. I wrote an article called "An Objectivist World" (I think). It discussed what a future world might look like. You could do that, or project a single person who has integrated and understood the ideas.