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