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