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