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