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