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