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