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