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