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