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