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