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