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