There is not a log of that for GM to see, like Pat said, far as I know too. Seeing the current players (or when someone joins) is easy, that's your Players list on your campaign details page. Seeing a list of everyone who has actually been in the game room itself not just joined the campaign's details page (probably including players who dropped out) may be possible with this little trick: Go to Add a new character in the journal, and look in the permissions drop down list ("Can Be Controlled By..."). This drop-down will usually, I think, show everyone who has ever clicked "Join Game" on your campaign, even if they subsequently departed. Could be wrong but I think it works that way. Other than that, You can just know / recognize / remember what players you had, and look at your list of current players, and decide if someone is missing. Maybe you have a thread "Everyone say hello" where everyone posts at least once. Maybe you have an LFG listing where everyone who wants to join must post once to apply for your game. Maybe you made a character sheet in-game for each participant. Those would be places you might have the previous/incoming players listed. Hope this helps. If you think you remember a specific player who might have dropped out, send them a message and ask 'em if they dropped on purpose or by mistake if they want to be re-invited back in.
