It is the same word (Adam meaning man) but the KJV translates it as men, any other translations I have checked translate it as 'Adam' himself.
What are the arguments for translating it as 'Adam'?
But they like men have transgressed the covenant: there have they dealt treacherously against me.
NASB (for example)
But like Adam they have transgressed the covenant; There they have dealt treacherously against Me.