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