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