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