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