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