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