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