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