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