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