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