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