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