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