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