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