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