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