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