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