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