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