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