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