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