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)(25,26,30,33)(27,32,36,31)(28,29,39,37)(34,40,38,35)(1,3)(2,6)(4,7)(5,8)(9,10,14,11)(12,15,20,17)(13,16,22,18)(19,23,21,24)(25,26,30,33)(27,32,36,31)(28,37,39,29)(34,35,38,40)(1,2,5,7)(3,6,8,4)(25,27,30,36)(26,31,33,32)(28,34,39,38)(29,35,37,40)(2,7)(4,6)(9,11,14,10)(12,15,20,17)(13,18,22,16)(19,23,21,24)(25,27)(26,32)(28,38)(29,35)(30,36)(31,33)(34,39)(37,40)(1,4)(2,3)(5,6)(7,8)(9,12,14,20)(10,15,11,17)(13,21,22,19)(16,24,18,23)(25,28,30,39)(26,29,33,37)(27,34,36,38)(31,35,32,40)(1,3)(2,6)(4,7)(5,8)(9,13,14,22)(10,16,11,18)(12,19,20,21)(15,23,17,24)(25,29)(26,28)(27,35)(30,37)(31,34)(32,38)(33,39)(36,40)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.