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