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