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