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)(11,23)(12,18)(13,19)(14,20)(15,21)(16,22)(17,24)(27,29)(31,33)(35,36)(38,39)(1,3,5,8)(2,6,7,4)(9,11)(10,17)(12,19)(13,20)(14,15)(16,24)(18,21)(22,23)(25,26,30,34)(27,31,29,33)(28,32,37,40)(35,38,36,39)(1,3)(2,4)(5,8)(6,7)(9,12,16,14)(10,18,22,20)(11,19,24,15)(13,17,21,23)(25,27,30,29)(26,31,34,33)(28,36,37,35)(32,39,40,38)(1,4)(2,3)(5,6)(7,8)(9,13,16,21)(10,19,22,15)(11,20,24,18)(12,23,14,17)(25,28,30,37)(26,32,34,40)(27,35,29,36)(31,38,33,39)(9,14,16,12)(10,20,22,18)(11,19,24,15)(13,17,21,23)(25,26)(27,31)(28,32)(29,33)(30,34)(35,38)(36,39)(37,40)(9,15,16,19)(10,21,22,13)(11,14,24,12)(17,18,23,20)(25,29,30,27)(26,33,34,31)(28,36,37,35)(32,39,40,38)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.