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