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