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