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