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