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