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