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