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)(15,21)(18,24)(22,23)(25,26)(27,34)(28,31)(29,37)(30,33)(32,39)(35,36)(38,40)(9,10)(11,16)(12,21)(13,17)(14,19)(15,20)(18,22)(23,24)(25,26,30,33)(27,28,31,34)(29,32,39,37)(35,36,40,38)(1,2)(3,5)(4,6)(7,8)(9,11)(10,14)(12,18)(13,19)(15,22)(16,17)(20,24)(21,23)(25,27,30,31)(26,28,33,34)(29,35,39,40)(32,36,37,38)(3,7)(5,8)(9,12,13,20)(10,15,17,21)(11,18,19,24)(14,22,16,23)(25,26)(27,28)(29,32)(30,33)(31,34)(35,36)(37,39)(38,40)(1,3)(2,5)(4,7)(6,8)(9,11)(10,16)(12,18)(13,19)(14,17)(15,23)(20,24)(21,22)(25,28)(26,31)(27,33)(29,38)(30,34)(32,35)(36,39)(37,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,10)(11,14)(12,15)(13,17)(16,19)(18,22)(20,21)(23,24)(25,29)(26,32)(27,35)(28,36)(30,39)(31,40)(33,37)(34,38) 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.