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