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