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