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