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