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