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