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)(11,17)(12,20)(13,15)(14,18)(16,21)(19,23)(22,24)(25,26)(27,32)(28,37)(29,39)(30,34)(31,36)(33,38)(35,40)(1,3,4,8)(2,5,6,7)(9,10)(11,14)(12,16)(13,15)(17,18)(19,22)(20,21)(23,24)(27,35)(28,36)(31,37)(32,40)(9,11,12,18,13,19,21,24)(10,14,16,17,15,22,20,23)(25,27,29,36,30,35,38,28)(26,31,33,32,34,37,39,40)(10,15)(14,22)(16,20)(17,23)(25,28,38,35,30,36,29,27)(26,32,39,31,34,40,33,37)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.