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