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