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