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