TL;DR: No, Darth Plagueis did not appear in Episode I: The Phantom Menace.

The character of Darth Plagueis simply did not exist until his creation for the Episode III script, and even then the mention was merely a plot device with which

Palpatine could lure Anakin towards the Dark Side of the Force, knowing full well of his concerns over losing Padme.

The novel you describe was written afterwards, and also explained that Plagueis was a Muun - a race introduced as far back as the "Hand of Thrawn" duology in 1997, but whose appearance had not been locked down until the appearance of San Hill in Episode II (pictured below).

I should also note that there is now some speculation among fans (not me, but others) that Grand Leader Snoke in Episode VII may actually be Darth Plagueis, meaning that he actually DID cheat death and wasn't killed as Palpatine believed. I doubt this is true, however, since he doesn't appear to be a Muun but some other similar-looking race with a shorter head.