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