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)(15,19)(16,20)(17,18)(21,22,25,26)(23,29,30,27)(24,32,33,28)(31,35,34,36)(2,4)(6,9)(10,11)(14,18)(19,20)(22,26)(23,30)(24,33)(35,36) involution — undirected(1,2,3,4)(13,15,17,16)(14,19,18,20)(21,22)(23,27)(24,28)(25,26)(29,30)(31,35)(32,33)(34,36)(5,7,8,12)(6,10,9,11)(13,16,17,15)(14,19,18,20)(21,23,25,30)(22,27,26,29)(24,34,33,31)(28,36,32,35)(5,6)(7,11)(8,9)(10,12)(13,14)(15,19)(16,20)(17,18)(21,24,25,33)(22,28,26,32)(23,31,30,34)(27,35,29,36)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.