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