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