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