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