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