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