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