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