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