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