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