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