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