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