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