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