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