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