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)(13,14,17,20)(15,23,26,19)(16,21,25,27)(18,22,24,28)(6,10)(11,12)(13,15)(14,19)(16,18)(17,26)(20,23)(21,28)(22,27)(24,25) involution — undirected(1,2,3,4)(5,7,9,8)(6,11,10,12)(14,20)(15,16)(18,24)(19,21)(23,27)(25,26)(5,7,9,8)(6,11,10,12)(13,16)(14,21)(15,24)(17,25)(18,26)(19,22)(20,27)(23,28)(5,8,9,7)(6,12,10,11)(15,25)(16,26)(18,24)(19,21)(22,28)(23,27)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.