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