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