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