One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(6,9)(10,12)(13,14,17,15)(16,18,20,19)(21,22)(23,27)(24,26)(25,32)(28,31)(29,33)(30,35)(34,36)(2,3)(6,9)(10,12)(14,15)(18,19)(21,23,26,31)(22,27,24,28)(25,30,33,36)(29,34,32,35)(1,3,4,2)(5,6)(7,10)(8,9)(11,12)(13,15,17,14)(16,19,20,18)(21,23)(22,28)(24,27)(25,30)(26,31)(29,35)(32,34)(33,36)(21,24,26,22)(23,27,31,28)(25,32,33,29)(30,34,36,35)(5,7,8,11)(6,10,9,12)(13,16,17,20)(14,18,15,19)(21,25,26,33)(22,29,24,32)(23,30,31,36)(27,34,28,35)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.