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