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