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)(11,15,16,13)(17,18,20,22)(19,21,23,24)(25,26,28,30)(27,34,35,31)(29,32,37,33)(36,39,40,38)(1,3,5,8)(2,6,4,7)(9,11)(10,13)(12,16)(14,15)(17,19)(18,21)(20,23)(22,24)(26,30)(31,34)(32,33)(38,39)(10,14)(13,15)(19,23)(21,24)(25,27,28,35)(26,31,30,34)(29,36,37,40)(32,38,33,39)(1,4,5,2)(3,6,8,7)(11,16)(13,15)(26,32)(29,37)(30,33)(31,38)(34,39)(36,40)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.