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)(15,24)(16,18)(17,25)(19,23)(20,27)(21,26)(22,28) involution — undirected(1,2)(3,4)(6,9)(7,11)(13,15,19,26)(14,21,23,24)(16,25,27,22)(17,18,28,20)(2,4)(13,16,18,14,19,27,20,23)(15,25,28,21,26,22,17,24)(6,9)(10,12)(13,17)(14,22)(15,18)(16,21)(19,28)(20,26)(23,25)(24,27) involution — undirected(2,4)(5,7,8,11)(6,10,9,12)(13,18,19,20)(14,16,23,27)(15,17,26,28)(21,22,24,25)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.