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