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