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