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