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