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