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