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