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