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