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