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