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