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