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