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