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