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