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