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