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