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