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