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