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