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