I can't figure out how to type the IPA symbols for it, but the proper (French) pronunciation is sais as in "says", o as in c'augh't, and the n is only there to denote that the "augh" vowel ought to be pronounced nasally.
That being said, most of the time when I hear bartenders or brewers around here attempt to say it they usually mispronounce it (they pronounce the n, the o comes out more like "cot" than "caught", they put the accent on the first syllable, etc.)