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