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)(15,21)(16,24,25,19)(17,20)(18,23)(22,27,28,26)(1,2)(3,4)(5,7,9,8)(6,10,11,12)(13,15)(14,18)(16,22)(17,23)(19,26)(20,21)(24,27)(25,28)(2,4)(5,8,9,7)(6,10,11,12)(13,15)(14,18)(16,22)(17,23)(19,26)(20,21)(24,27)(25,28)(13,16)(14,19)(15,22)(17,25)(18,26)(20,24)(21,27)(23,28) 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.