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