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