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