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