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