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