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