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