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