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