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