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