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