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