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