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