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