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