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