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