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