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