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