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