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