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