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