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