A Google Webmaster Help thread has a searcher asking Google how they can remove a Facebook page from Google. The page has been deleted from Facebook, but it still shows up in the Google Cache.
Googler, Wysz, gave the searcher a detailed explanation of how he can remove this Facebook page. I'll quote him word for word:
In this case, you'll want to do a cache removal request, which does not require the page to return a 404; it just requires that the webmaster modifies the content. While going through the steps documented in the help link below, you'll want to choose "The site owner has modified the page..." option. Make sure you include the correct URL (the Facebook page you mentioned, not the URL of Google's cache) and only mention terms that were on the page but are no longer there. (Don't use "Facebook" as a term, as that is likely still on the page.)
So go to this document to learn more and if you have questions, hit Wyzs up in the thread.
Forum discusison at Google Webmaster Help.