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