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