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