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