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