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)(11,21,23,16)(12,18,13,17)(14,22,24,19)(27,34)(29,37)(31,32)(33,36)(1,3)(2,6)(4,7)(5,8)(9,11)(10,16)(12,22)(13,19)(14,18)(15,23)(17,24)(20,21)(25,26)(27,32)(28,30)(29,33)(31,34)(35,39)(36,37)(38,40) involution — undirected(9,12,15,13)(10,17,20,18)(11,22,23,19)(14,16,24,21)(25,27)(26,31)(28,32)(29,35)(30,34)(33,38)(36,39)(37,40)(2,4)(6,7)(9,13,15,12)(10,18,20,17)(11,22,23,19)(14,16,24,21)(25,28,30,26)(27,32,34,31)(29,36,37,33)(35,39,40,38)(1,4,5,2)(3,7,8,6)(9,14,15,24)(10,19,20,22)(11,18,23,17)(12,16,13,21)(25,27)(26,32)(28,31)(29,35)(30,34)(33,39)(36,38)(37,40)(1,3)(2,6)(4,7)(5,8)(9,10)(11,16)(12,17)(13,18)(14,19)(15,20)(21,23)(22,24)(25,29)(26,33)(27,35)(28,36)(30,37)(31,38)(32,39)(34,40) involution — undirectedA 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.