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