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