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