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