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