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