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