One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,12)(8,10)(9,11)(13,14)(15,18)(16,24)(17,25)(19,23)(20,26)(21,27)(22,28) involution — undirected(1,2)(3,4)(5,7,9,8)(6,10,11,12)(13,15,18,14)(16,25,17,24)(19,22,28,23)(20,26,21,27)(13,16,18,17)(14,20,15,21)(19,27,28,26)(22,25,23,24)(2,4)(5,8,9,7)(6,10,11,12)(13,17,18,16)(14,21,15,20)(19,26,28,27)(22,24,23,25)(6,11)(10,12)(14,15)(16,17)(22,23)(26,27) involution — undirectedA 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.