The only place on your site where you might place a link (or URL reference) to your XML sitemap is in your robots.txt file. This will allow Google and all the other search engines you've not explicitly submitted a sitemap to, that support this extended robots.txt syntax, to find your XML sitemap:
Absolute or relative URL?
As mentioned in comments, the specification defines it as an absolute URL, however, the StackExchange network use a root-relative URL:
# this technically isn't valid, since for some godforsaken reason
# sitemap paths must be ABSOLUTE and not relative.