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