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