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