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