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