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)(11,19)(12,18)(13,15)(14,17)(16,20)(21,24)(22,23)(25,26,30,28)(27,31,34,36)(29,37,39,32)(33,35,40,38)(1,3,4,8)(2,5,6,7)(10,15)(16,23)(17,18)(19,24)(25,27)(26,31)(28,36)(29,38)(30,34)(32,40)(33,37)(35,39)(9,11)(10,16)(12,20)(13,21)(14,22)(15,23)(17,19)(18,24)(25,28,30,26)(27,33,34,40)(29,32,39,37)(31,38,36,35)(2,6)(5,7)(9,12,13,14)(10,17,15,18)(11,20,21,22)(16,19,23,24)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.