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