One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(10,14)(11,17)(12,19)(22,24)(25,26,30,28)(27,31,33,35)(29,36,37,32)(34,40,39,38)(6,8)(11,17)(15,20)(18,23)(22,24)(26,28)(27,33)(32,36)(34,39) involution — undirected(5,6)(7,8)(9,10,13,14)(11,15,17,20)(12,16,19,21)(18,22,23,24)(25,27)(26,31)(28,35)(29,34)(30,33)(32,38)(36,40)(37,39)(1,2)(3,4)(9,11)(10,15)(12,18)(13,17)(14,20)(16,22)(19,23)(21,24)(25,28,30,26)(27,31,33,35)(29,32,37,36)(34,40,39,38)(9,12)(10,16)(11,18)(13,19)(14,21)(15,22)(17,23)(20,24)(25,29,30,37)(26,32,28,36)(27,34,33,39)(31,38,35,40)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.