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