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