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