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