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