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