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