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)(11,20)(12,16)(13,19)(14,18)(15,23)(17,22)(21,24)(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)(10,16)(12,14)(13,22)(15,21)(17,23)(18,20)(19,24)(25,27)(26,30)(28,33)(29,35)(31,37)(32,39)(34,36)(38,40)(9,12,14,11)(10,17,18,24)(13,22,15,21)(16,19,20,23)(27,33)(28,36)(30,37)(31,40)(34,35)(38,39)(1,4,5,6)(2,3,7,8)(9,13)(10,18)(11,21)(12,22)(14,15)(17,24)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.