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