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