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