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