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