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