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