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