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