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