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