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