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