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