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