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