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