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