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