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