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