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