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