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