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