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