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