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