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