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