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