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