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