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