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