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