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