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