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)(11,17)(12,16)(13,15)(14,18)(19,23)(20,22)(21,24)(25,26,30,34)(27,31,36,39)(28,32,29,33)(35,38,37,40)(2,5)(6,8)(9,10)(11,14)(12,16)(13,15)(17,18)(19,21)(20,22)(23,24)(25,27,30,36)(26,31,34,39)(28,37,29,35)(32,40,33,38)(1,3,4,7)(2,6,5,8)(9,11)(10,14)(12,19)(13,18)(15,17)(16,21)(20,24)(22,23)(25,27)(26,31)(28,35)(29,37)(30,36)(32,38)(33,40)(34,39)(10,15)(14,17)(16,22)(21,23)(25,28,30,29)(26,32,34,33)(27,35,36,37)(31,38,39,40)(11,18)(14,17)(19,24)(21,23)(25,29,30,28)(26,33,34,32)(27,35,36,37)(31,38,39,40)(9,12,13,20)(10,16,15,22)(11,19,18,24)(14,21,17,23)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.