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