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