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