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