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