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