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