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