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