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