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