When research that will be published with multiple names on it is presented by someone, I think the most appropriate thing to do is list all of the names of the people who did the research and mark whoever the person/people who presented it with "(presenter)." For example:
Alpha, Beta (presenter), and Gamma. On the Naming Family "-yan", Oral Presentation at the North American Conference for Naming Conventions.
I would do this both on listings where you presented and on listings where you didn't. The motivation here is that the act of giving the presentation is rarely what you're getting credit for. What you're getting credit for is the research and potentially the fact that you were invited to present the research at the conference. This is true of you even if you weren't the person who went.