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