Any cable, or
no cable that anyone can identify as Mac-related?
I am assuming this is not a business presentation at a site with an "established" projector. In those instances, I always been able to depend on the IT/PR folks to solve any connection problem.
I'd get the brand name of the projector and then call Customer Support at the manufacturer. Tell them your Mac model and OS and they should be able to answer your query + reduce any anxiety you may have.
I put a PP show together in San Francisco and ran it at a private party on a borrowed projector in Ohio, last year, where the owner of the projector (a Windozeperson) didn't have a clue. . . only the model number.
Calling In-Focus, in Portland with the model nr produced instant help confirming how to connect it to my Pismo, plus (more importantly) how and which control panels to adjust for the desired, projected results. . . in your case, Prefs Panels.
Some glitches in adding more slides at the last minute (in Ohio) were solved by calling Pendragon for some OS/SW advice.
TeeEss to the Rescue . . .again!