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