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