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