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