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