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