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