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)(25,26,29,33)(27,34,30,31)(28,36,37,32)(35,39,38,40)(1,3,4,8)(2,5,6,7)(9,11)(10,14)(12,18)(13,17)(15,20)(16,21)(19,23)(22,24)(25,27,29,30)(26,31,33,34)(28,35,37,38)(32,39,36,40)(11,17)(14,20)(18,23)(21,24)(26,31)(27,30)(32,39)(33,34)(35,38)(36,40) involution — undirected(10,15)(14,20)(16,22)(21,24)(25,28,29,37)(26,32,33,36)(27,35,30,38)(31,39,34,40)(9,12,13,19)(10,16,15,22)(11,18,17,23)(14,21,20,24)(28,37)(32,36)(35,38)(39,40)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.