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