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