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