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