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