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