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