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