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