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