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