I'm looking for an Image of the palatine apollo alter relief depicting
apollo, latona, and diana with an exhausted sibyl

Dear arduser,

please follow this link. It will lead you to a website with a large
photograph of the relief from the Apollo Palatinus altar in Rome,
depicting the scene you described:
http://ls10-www.informatik.uni-dortmund.de/~fronk/Pharos/Bilder/ARCH/Rom/Palatin/ARCH-K-PalApTKultbgr.html

The German text under the image reads:
"Reflex of the cult image group from the temple of Apollo Palatine:
Diana, Apollo, and Latona. In the background a tripod, in the
foreground, sitting on the floor, Sybil symbolizing the Sybilian Books
which were kept in the pedestal of the cult image's base."

In case the website link does not work properly, here is a direct link
to the photograph of the relief:
http://ls10-www.informatik.uni-dortmund.de/~fronk/Pharos/Bilder/ARCH/Rom/Palatin/JPG/ARCH-K-PalApTKultbgr.jpg

Source:
University of Dortmund: Augusteisches Rom - Augustus und der Palatin, Page 4
http://ls10-www.informatik.uni-dortmund.de/~fronk/Pharos/Rom/Archaeologie/Palatin/ARCH-K-APT3.html

Search terms used:
apollo palatin relief
://www.google.de/search?hl=de&ie=UTF-8&oe=UTF-8&newwindow=1&q=apollo+palatin+relief&meta=


Hope this is what you were looking for!
Best regards,
Scriptor

Thank you. This is what I was looking for.