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