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