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