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