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