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