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