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