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