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