One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6,8,9)(7,10,11,12)(13,14)(15,17)(16,18)(19,20)(21,22,25,28)(23,26,30,34)(24,27,31,35)(29,33,32,36)(6,9)(10,12)(13,15,16,19)(14,17,18,20)(23,29)(24,31)(26,33)(27,35)(30,32)(34,36)(14,18)(17,20)(21,23,25,30)(22,26,28,34)(24,32,31,29)(27,36,35,33)(2,4)(5,7,8,11)(6,10,9,12)(23,30)(26,34)(29,32)(33,36)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.