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