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