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)(11,14)(12,19)(13,15)(16,21)(17,23)(18,24)(20,22)(25,26,30,31)(27,32,35,29)(28,33,38,39)(34,40,36,37)(2,5)(6,7)(9,11,13,17)(10,14,15,23)(12,20,21,18)(16,24,19,22)(26,31)(29,32)(33,39)(37,40)(1,2)(3,6)(4,5)(7,8)(10,15)(11,17)(16,19)(18,20)(25,27,30,35)(26,32,31,29)(28,36,38,34)(33,37,39,40)(1,3,4,8)(2,6,5,7)(9,10)(11,14)(12,16)(13,15)(17,23)(18,22)(19,21)(20,24)(25,27)(26,29)(28,34)(30,35)(31,32)(33,37)(36,38)(39,40)(9,11)(10,14)(12,18)(13,17)(15,23)(16,22)(19,24)(20,21)(25,28,30,38)(26,33,31,39)(27,34,35,36)(29,37,32,40)(9,12,13,21)(10,16,15,19)(11,18,17,20)(14,22,23,24)(25,29)(26,27)(28,37)(30,32)(31,35)(33,34)(36,39)(38,40)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.