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