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