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