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