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