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