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