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