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