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