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