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