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