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