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