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