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