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