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