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