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