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