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