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