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