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