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