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