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