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