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