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