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