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