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