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