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