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