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