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