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