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