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