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