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