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